This invention relates generally to methods and systems for providing electrical power, in particular, methods and systems for providing temporary or supplemental electrical power to supplement or replace an existing power supply.
The electrical demands of residential and commercial buildings have been traditionally powered via connection to a utility grid of power lines transporting electricity from a central generation facility. Increasingly, utility grids are being supplemented or even replaced by distributed generation systems, which can provide power in closer proximity and relation to specific power demands. For example, an on-site fuel cell system can be used to power a residential or commercial building or other application, eliminating the need for connection to a utility grid. Distributed generation systems can also be used in conjunction with the utility grid, to accommodate peak electrical demands, as an example.
Fuel cell systems and other distributed power generation systems, as well the utility grid itself, may require periodic maintenance. In many residential and commercial applications for electricity, it may be desirable to switch off an existing power supply for maintenance, while switching on a secondary power supply in such a way that appliances can maintain uninterrupted operation.
The present invention generally includes methods and systems for providing a source of electrical power, for example, on a temporary basis. This source of power can be provided to a load, for example, to a building or appliance, otherwise powered by an existing power supply during servicing or power outages. The present invention may also be used as stand-alone source of power, for example, at a construction site, at the site of a medical emergency, or to a remote location. The temporary or supplemental power source according to the present invention is portable so that it can be easily transported to the location where needed. When supplementing or replacing the electrical power of an existing power supply system, the power supply of the present invention is quickly and easily interfaced with the existing power supply system. Though these systems and methods can typically be used temporarily or for a limited amount of time, it will understood by those of skill the art that under certain conditions, these systems and methods may also be used for extended periods of time, for example, for days, weeks, months, or even years.
One embodiment of the present invention is a method of supplying power to a load having an existing power supply, in which the method includes or comprises: providing a portable power supply having a power synchronizing device; activating the power synchronizing device to synchronize the power from the existing power supply and the portable power supply; and providing power from the portable power supply to the load.
A further embodiment of the present invention is a method for servicing an existing power supply system, including or comprising: providing a portable power supply and a power synchronizing device; connecting the existing power supply system and the portable power supply to the power synchronizing device; activating the power synchronizing device to synchronize the power from the existing power supply system and the portable power supply; providing power from the portable power supply to the load; shutting down the existing power supply; and servicing the existing power supply system while the load is powered by the portable power supply.
A still further embodiment of the present invention is a system for providing power to a load powered by an existing fuel-cell-type power supply, said system comprising: a portable fuel-cell-type power supply; and a power synchronizing device having at least a first power input connectable to the portable power supply and a second power input connectable to the existing power supply, and a power output connectable to the load. The portable fuel-cell-type power supply system and the existing fuel-cell-type power supply convert at least one of a hydrocarbon fuel and hydrogen to electric power. The hydrocarbon fuel is selected from the group of fuels consisting of methane, propane, methanol, ethanol, and natural gas.
In one example, when the portable power supply according to the present invention is used to replace or supplement an existing power supply, the existing power supply and the portable power supply are preferably both fuel-cell type power supplies. In particular, the power supplies preferably both include one or more PEM-type fuel cells, or one or more PEM-type fuel cell stacks.
Other features, objects, and advantages of the invention will be apparent from the drawings, description, and claims.